Conventionally, a capped container in which a cap is attached to a container body has been provided.
FIG. 1 is a sectional view of a main portion of a conventional capped container.
As shown in FIG. 1, a cap Cp is attached to a top wall of a container body 11, and the container body 11 and the cap Cp constitute a capped container. The cap Cp includes a base flange 15; a movable tube 16, which is disposed in the base flange 15 rotatably and in a reciprocatory condition (in FIG. 1, in a vertically movable condition); and a screw cap 17, which is disposed outside the base flange 15 rotatably and in a reciprocatory condition.
At the time of unsealing the capped container, a rupture portion 12 formed on the top wall of the container body 11 is cut to thereby form an outlet 11A. The base flange 15, which includes a lower flange portion 13 and an upper tubular portion 14 formed integrally with the flange portion 13, is fixedly attached along an upper peripheral edge of the rupture portion 12.
In the tubular portion 14, a female thread 14A is formed on the inner surface in a region extending from substantially the vertical center to the lower end, and a male thread 14B is formed on the outer surface in a region extending from substantially the vertical center to the upper end. In the movable tube 16, a plurality of ribs 16A are formed on the inner surface at predetermined circumferential pitches and in a vertically extending condition, and a male thread 16B is formed on the outer surface. A single pointed tip portion 18 for cutting the rupture portion 12 is formed at the lower end of the movable tube 16 at a predetermined circumferential position in a downward projecting condition.
The screw cap 17 includes a top wall 21, and a side wall 22 extending downward from the peripheral edge of the top wall 21. A female thread 22A is formed on the inner surface of the side wall 22. In the screw cap 17, a plurality of arms 23 are formed at predetermined positions located radially inward of the side wall 22 in such a manner as to extend downward from the top wall 21 and at the same pitches as those of the ribs 16A so as to correspond to the ribs 16A. In each of the arms 23, a longitudinally extending engagement piece 24 is formed on the radially outward surface at the lateral center, and a rib 25 is formed on the radially inward surface at the lateral center in such a manner as to extend from substantially the longitudinal center to the upper end.
The tubular portion 14 and the movable tube 16 are thread-engaged with each other by means of the female thread 14A and the male thread 16B; the tubular portion 14 and the side wall 22 are thread-engaged with each other by means of the male thread 14B and the female thread 22A; and the movable tube 16 and the arms 23 are engaged together by means of the ribs 16A and the corresponding engagement pieces 24. Notably, the female thread 14A and the male thread 16B are inverse in helix to the male thread 14B and the female thread 22A. In other words, the female thread 14A and the male thread 16B are right-handed threads, whereas the male thread 14B and the female thread 22A are left-handed threads.
Accordingly, in the initial state of the cap Cp, rotating the screw cap 17 in the tightening direction causes the screw cap 17 to move downward, since the tubular portion 14 and the side wall 22 are thread-engaged. In association with this, the arms 23 are caused to move downward, so that the ribs 16A and the corresponding engagement pieces 24 are engaged with each other. Subsequently, as the screw cap 17 is rotated, the movable tube 16 is caused to rotate in the same direction. In this case, since the tubular portion 14 and the movable tube 16 are thread-engaged, the movable tube 16 is caused to move upward while being rotated.
Meanwhile, when the screw cap 17 is rotated in the loosening direction, the screw cap 17 is moved upward. In association with this, the arms 23 are moved upward while the ribs 16A and the corresponding engagement pieces 24 are engaged with each other, so that the movable tube 16 is rotated in the same direction. As the movable tube 16 is rotated, the movable tube 16 is caused to move downward, so that the pointed tip portion 18 cuts the rupture portion 12 to thereby unseal the capped container (refer to, for example, Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-Open (kokai) No. 2001-106248